/*
 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.beans;

import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.lang.reflect.Method;

import static sun.reflect.misc.ReflectUtil.isPackageAccessible;

final class MethodRef {

  private String signature;
  private SoftReference<Method> methodRef;
  private WeakReference<Class<?>> typeRef;

  void set(Method method) {
    if (method == null) {
      this.signature = null;
      this.methodRef = null;
      this.typeRef = null;
    } else {
      this.signature = method.toGenericString();
      this.methodRef = new SoftReference<>(method);
      this.typeRef = new WeakReference<Class<?>>(method.getDeclaringClass());
    }
  }

  boolean isSet() {
    return this.methodRef != null;
  }

  Method get() {
    if (this.methodRef == null) {
      return null;
    }
    Method method = this.methodRef.get();
    if (method == null) {
      method = find(this.typeRef.get(), this.signature);
      if (method == null) {
        this.signature = null;
        this.methodRef = null;
        this.typeRef = null;
      } else {
        this.methodRef = new SoftReference<>(method);
      }
    }
    return isPackageAccessible(method.getDeclaringClass()) ? method : null;
  }

  private static Method find(Class<?> type, String signature) {
    if (type != null) {
      for (Method method : type.getMethods()) {
        if (type.equals(method.getDeclaringClass())) {
          if (method.toGenericString().equals(signature)) {
            return method;
          }
        }
      }
    }
    return null;
  }
}
